The present invention relates to a liquid crystal display device; and, more particularly, to a so-called vertical orientation type liquid crystal display device.
A liquid crystal display device is configured such that the optical transmissivity of a liquid crystal material in each pixel region is controlled in response to an electric field which is generated between a pair of electrodes and is applied to the liquid crystal material.
In such a liquid crystal display device, orientation films are arranged so as to be directly brought into contact with the liquid crystal material, thereby to determine the initial orientation direction of the liquid crystal when an electric field is not applied to the liquid crystal.
Further, although the orientation films conventionally require orientation treatment by rubbing, there is a liquid crystal mode which requires no rubbing treatment and can omit step for such a treatment, and a so-called vertical orientation type liquid crystal display device has been developed (see Japanese Patent Laid Open 11-72793, 11-109355, 11-352489, for example) on the basis of such a liquid crystal mode.
That is, with the use of so-called vertical orientation films, without use of rubbing treatment, liquid crystal molecules are arranged in the vertical direction with respect to the substrates when no electric field is applied to the liquid crystal material, and these molecules are tilted down in a plurality of directions when an electric field is applied to the liquid crystal material.
Here, due to such tilting-down of the liquid crystal molecules in a plurality of directions, the vertical orientation type of device has a feature in that a broad viewing angle can be simultaneously achieved as part of the liquid crystal display characteristics.